Another teenage girl who want to be a boy

This is my first post on mumsnet! I have read and reread other post on girls with gender dysphoria and have gained a lot of support, so here goes! Our daughter told us about 6 months ago that she felt she should be a boy and the only way forward was to transition fully. She was 14 then, now 15. I was totally devastated and utterly lost. I had felt that something was on the horizon as she had asked for a hair cut and started wearing boyish clothes a few months previous. We didn't know what to do so suggested she give herself 6 months to think about things. We did take her to the GP though as I thought counselling might help. She was referred to CAMHS and the psychologist told us that she wasn't convinced by our daughter and that we should come back to her in a year or so. Thank god for the voice of reason, I thought! We did get referred for counselling which was not helpful because she wasn't given any strategies to help deal with her feelings. The last six months have seen her become socially isolated, depressed and she has developed an eating disorder. We are now back at CAMHS with the eating disorder nurse and hopefully soon for a more thorough assessment of her mood, OCD behaviours etc. I completely fell apart at the beginning but seem to have convinced myself that this, although very real for her at the moment, won't persist and so am better able to cope. I believe this is sudden onset gender dysphoria, she never showed any discomfort with being a girl until a few months before she told us. as a small child she was very girly, she became a tom boy for a while a primary school but never asked for boys clothes. As soon as she left primary school it was earrings, make up, hair styles etc. She embraced puberty and it doesn't seem long ago she was moaning that I wouldn't buy underwired bras. I feel as if she was struck with a thought one day that has taken hold and drawn her in. She is sad, lonely and lost and so are we. We still use her name and refer to her as she because although we know she doesn't like this she won't let us tell anyone, even her siblings so we have no choice. I know that she is totally convinced that the only way to be happy is if someone can wave a magic wand and she can leave the house tomorrow a boy. How that would help I have no idea as she would then be a girl in a boys body! She has never had any typically male interests, has an older brother but never shown an interest in his things and all her friends are girls, how could she relate to people if she was a boy? I don't know how to help her though this. We have said that we will support if she still feels this way as an adult but I can't give permission for any medical interventions when I am not convinced that this is a permanent thing. She has always been one to reinvent herself every now and then and I suppose that is what I am hoping for, that she finds a way back to being happy being herself. But how???